Pusher for polygonal-shaped stock



April 1956 A. A. ABRAMOSKA 2,741,482

PUSHER FOR POLYGONAL-SHAPED STOCK Filed July 24, 1953 INVEN TOR.

ALFRED A. ABRAMOSKA United States Patent PUSHER FOR POLYGONAL-SHAPED STOCK Alfred A. Abramoska, Cleveland, Ohio Application July 24, 1953, Serial No. 370,033

3 Claims. (Cl. 279-41 My invention relates to pushers for feeding polygonalshaped bar stock into machine tools, such as automatic screw machines. 7

An object of my invention is the construction of a pusher arranged to accommodate polygonal-shaped stock having maximum cross-sectional dimensions relative to the polygonal-shaped bore in which the stock is held by the pusher.

Another object is the provision for relieving the wall of the pusher in a location rearward of the polygonalshaped bore to accommodate the corners of complementary shaped and sized stock.

Another object is the provisions of construction in a pusher made to accommodate maximum size polygonalshaped stock at its forward end in which the wall of the pusher has spaces formed therein for accommodating the corners of the polygonal-shaped stock inserted into the bore prior to the expansion of the pushers resilient fingers.

Another object is the provision of means for providing for the maximum size of polygonal stock relative to the internal diameter of the pusher.

Still another object is the provision for increasing the capacity of a pusher for polygonal-shaped stock without a proportional increase in the size of the pusher.

Other objects and a fuller understanding of the invention may be had by referring to the following description and claims, taken in conjunction with the accompanying drawing, in which:

Figure l is a longitudinal cross-section of a pusher embodying my invention and having a piece of polygonalshaped stock being advanced into feeding position;

Figure 2 is a view of the forward end of my pusher shown partly in elevation and partly in section in which the pusher shown in Figure 1 has been rotated upon its axis about 90 degrees; and

Figure 3 is an enlarged cross-sectional view taken through the line 3-3 of Figure 1.

In the following discussion, the word polygon is used in its broadest sense so as to include three-sided, four-sided, five-sided and other sided figures and shapes, as well as the six-sided figure illustrated in the drawing.

in the drawing, the pusher is denoted generally by the reference character 11. The pusher is carried upon a supporting member or tube 12 carried by the machine. A piece of bar stock having a hexagon shape in crosssection is denoted by the reference character 13.

The pusher 11 has two longitudinal slits 14 extending rearwardly from the forward end thereof. These slits 14 form two opposing fingers. The pusher is a steel tube and the fingers are heat-treated and compressed so as to be resilient and contracted or biased radially inward in the usual manner.

At the forward end portion of the pusher, there are six pad portions 15 surrounding a stock-receiving bore 16 of hexagon shape. As the stock 13 is hexagonal in shape, there are six pad portions 15. The maximum corner-to-corner dimension of the bore 16, when the ice fingers-are in anexpanded condition by the presence of stock 13 within the bore 16, is approximately the same as the maximum corner-to-corner dimension of the stock 13. When the fingers are in their resiliently contracted condition, then the bore 16 is somewhat less in crosssectional area than the cross-sectional area of the stock 13.

It is to be noted that by reason of the contraction of the fingers formed by the slits 14, the walls of the fingers are inclined toward each other in a gradual slope from about the middle of the pusherto the forward end of the pusher. This inclination of the walls of the pusher is such that not only the bore 16 is smaller than the cross-sectional area of the stock 13 when the fingers are in contracted condition, but also the bore of the pusher rearwardly of and adjacent the polygonal-shaped bore 16 is of gradually reduced cross-sectional area. This reduced cross-sectional area of the pushers bore from about midway between its ends to the pads 15 around the bore 16, is such that the pusher cannot readily accommodate polygonal-shaped stock, such as the hexagonshaped stock 13, when the bore 16 has been made of a size approaching the maximum inner diameter of the pusher.

To accommodate stock of such cross-sectional dimensions as such dimensions approach the maximum inner diameter of the bore of the pusher, it has'previously been necessary to enlarge the size of the pusher. However, I provide means for maintaining the size of the pusher while accommodating relatively large sizes of stock by'relieving the 'walls of the pusher at the location of its gradually diminished diameter resulting from the contraction ofthe fingers. This is preferably. .done by providing a plurality of slots 17 which are cut through the wall of the pusher and extend approximately from the location of the pusher where the diameter starts to gradually decrease in cross-sectional. area to approximately the location where the bore16, defined by the pad portions 15, commences.

In the case of hexagon-shaped stock, the wall of the bore should be relieved at about six equidistantly spaced points around the circumference of the bore. Two of these points are provided by the slits 14 and four of these points for relief are provided by the slots 17. Thus, together, there are six open spaces in which the outer corners of the stock may protrude. The corners will not necessarily protrude into all of these open spaces at once, but these spaces are located for the accommodation of the corners as they may protrude. By providing six recesses or open spaces through the combination of slots and slits, hexagon-shaped stock of maximum dimension from corner to corner may be accommodated in a pusher in which the maximum dimension form corner to corner of the bore 16 approaches or approximates the minimum diameter of the round bore in the pusher rearwardly of the polygonal-shaped bore 15.

The edges of the several slots 17 and slits 14 engaged by the angular corners of the hexagon-shaped stock 13 provide camming surfaces which guide the stock in its forward motion up into the restricted bore 16. The hexagon-shaped stock rides along on the edges of the slots and slits in its forward travel and as the stock is moved forwardly, the fingers expand or move apart so as to accommodate the stock within the bore 16. Thus, the walls of the slots 17 and slits 14 provide means for guiding the hexagon-shaped stock into its proper position within the polygonal-shaped bore 16.

By the use of the construction shown, a pusher of a predetermined outside dimension can accommodate bar stock of relatively large cross-sectional area. in the absence of the invention, the same size bar stock would have to be accommodated in a pusher of considerably larger diameter.

Those acquainted with the construction and uses of pushers will readily appreciate and recognize the distinct benefits and advantages that are obtainable with the improved construction here disclosed.

This disclosure includes the disclosure contained in the appended claims, as well as the disclosure found' in the above description and in the drawing.

Although this invention has been described in its preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form has been made only by way of example and that numerous changes in the details of construction and the combination and arrangement of partsmay be resorted to without departing'from the spirit and scope of the invention as hereinafter claimed.

What is claimed is:

1. In a pusher having longitudinal slits extending from the forward end' thereof forming resilient and gradually contracted fingers, a pad portion at its forward end, the

pad portion having a polygonal-shaped bore to accommodate stock of' polygonal-shaped cross-section, said pusher having a cylindrical bore extending rearwardly from said pad portion, the improvement of providing relief in the inner wall' of the pusher for accommodating.

all the corners of the polygonal-shaped stock, said relief in addition to said slits comprising open spaces in said pusher wall extending longitudinally of the pusher along' a portion of said cylindrical bore and the next adjacent portion of said polygonal-shaped bore, said open spaces terminating rearwardly of the forward end of said-pusher, said open spaces together with said slits expand said fingers andto enlarge the polygonal-shaped bore to receive the polygonal-shaped stock.

2. In a pusher for polygonal-shaped stock, the pusher 7 having slits extending longitudinally from its forward end,

said slits dividing the pusher into resilient contracted fingers, the pusher having a pad portion at its forward end, said pad portion having a polygonal-shaped bore in the contracted condition of the pusher, said polygonalshaped bore being smaller than the cross-sectional area of the stock and adapted to be enlarged by insertion of the stock therein to receive, and complementarily interfit with, said stock, said pusher having a cylindrical bore extending rearwardly of the pusher from said polygonal-shaped bore, the cylindrical bore gradually decreasing in dimension forwardly toward the polygonal-shaped bore in the contracted condition of the pusher, the improvement of a plurality of slots extending through the pusher wall and slits together being arranged substantially equidistantly from each other in a circumferential direction and together corresponding in number'with the number of corners of the polygonal-shaped bore, said slots extending rearwardly of the pusher from a location between the ends of the polygonal-shaped bore to a location along the cylindrical bore rearwardly of the polygonal-shaped bore, said slots and slits accommodating the corners of the polygonal-shaped stock as it is moved forwardly through the pusher into said polygonal-shaped bore and as the stock gradually expands the resilient fingers in moving through the cylindrical bore into the polygonal-shaped bore.

3. A pusher having resilient contracted fingers at its forward end expandable by stock advanced into the pusher between said fingers from the rearward end of the pusher, said pusher having a forward end portion adapted to engage and complementarily interfit with 'said stock, the contracted fingers causing a gradually contracted condition of the pusher at a location next rearwardly of said forward end portion and extending gradually into said forward end portion, the improvement of providing retion rearwardly of said forward end portion, said open spaces corresponding in number and spaced arrangement with the outer corners of the stock being accommodated to permit said cornersto enter said open spaces, respectively, upon-insertion of said stock into the pusher before expansion of said fingers, said open spaces extending forwardly from said location of contracted condition into said forward end portion and terminating rearwardly of the forward end of said pusher to provide said relief for said stock in its initial introduction into said forward end portion from the rear through said location of con-' tracted condition.

References Cited in the tile of this patent UNITED STATES PATENTS 

